Greek authorities transferred about 1,000 undocumented immigrants an area close to the Turkish border Aug. 7, after a weekend police sweep in Athens led to a mass arrest of foreigners.

A local police official said the immigrants were being held in two temporarily closed police schools in Thrace, a part of northeastern Greece bordering Turkey, Agence France-Presse reported. It’s unclear how long the immigrants will remain in the centers, as recession-choked Greece has scant money to return them to their home countries. Greek government figures show more than 100 migrants crossing the country’s border with Turkey daily. Turkey and the European Union formally launched the visa-exemption process for Turkish citizens last June and initiated a readmission agreement with the bloc. The deal envisages the repatriation of illegal migrants in Europe via Turkey after temporary stays in the latter country, in response to key steps outlined by the EU for a visa-free agreement with Turkey.

Minister for Citizen Protection Nikos Dendias called on regional mayors to back the transfer, a day after they protested the police school closures in the city of Komotini. Dendias said he was committed to keeping the schools open and that the transfer of the immigrants to the facilities was “a provisional step to resolve the problem of illegal immigrants,” which he called a “question of national survival.” “In the name of your patriotism and the instinct for the survival of the Greek citizen, I ask for your support for this effort.”

According to the latest tallies, more than 6,000 people were questioned during the Athens crackdown. A total of 1,595 of them were arrested and face deportation.